Skilled craftsman's perch over in Irish islands (7)
I believe the answer is:
artisan
'skilled craftsman's' is the definition.
(I've seen this in another clue)
'perch over in irish islands' is the wordplay.
'perch' becomes 'sit' (I've seen this in another clue).
'over' shows that the letters should be reversed in order.
'in' is an insertion indicator.
'irish islands' becomes 'aran' (I've seen this in another clue).
'sit' back-to-front is 'tis'.
'tis' placed inside 'aran' is 'ARTISAN'.
(Other definitions for artisan that I've seen before include "Mechanic" , "Crafty sort" , "Smith" , "Skilled worker or craftsman" , "craftsman of his trade" .)